Pontiac GTO Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter #1
I know what I make at the wheels, but am curious if we have a 'guesstimate' of what % is actually lost through the drivetrain. I know vettes are low with about 12-15% loss. Any idea how the GTO's match up?
 

·
Registered
Joined
·
351 Posts
yep a guy that is 7 time world champ in street car racing says you lose 22% through the drivetrain with all cars.
 

·
Registered
Joined
·
3,765 Posts
I think FWD, RWD, and AWD all have different loses from drivetrain. Plus there is different amounts lost from auto to manual too. I would estimate thar RWD M6 woudl be arround 15-20%. Stock I was at 304... rated at 350 per GM... so thats about 13% assiming no error, different dynos, ect...
 

·
Premium Member
Joined
·
4,162 Posts
So many variables its not funny. Not all cars are going to be the same so there is no set precentage.

The only true way to find out is have the engine dynoed record those numbers, stick it back in and record the numbers on an chassis dyno. Thats the way to find out numbers for your car.:willy:;)


People usally go by 12-15% for manuals and 15-20% for autos.
 

·
Registered
Joined
·
342 Posts
As said, so many factors...

even having a solid driveshaft or the stock 2pc is going to make a difference.
 

·
Registered
Joined
·
96 Posts
many variables

I know with an automatic - 13-16% loss
Stick is less of a % loss
Rear diff. be interesting to know the % loss difference, if any, between a solid axle vs IRS
for instance, i know the ford 9" is a power eater, compared to the 8.8" almost a 6% difference
I have a Gear Vendor O/D on my trans, briefly, the GV unit allows you to "split" each gear, i.e. -1st-1st over, 2nd-2nd over & so on.
So, a 3 speed becomes a 6 speed ,a 4 speed becomes an 8 speed!
When shifting you only loose approx. 200-300 rpm on each shift, so your engine is always in its sweet power band.
Gear Vendors states the unit is so efficent you only loose 1% for every 400hp!
 

·
Registered
Joined
·
19 Posts
Discussion Starter #7
roy-
That is a sick setup! That makes me think of a big rigs's set up with high and low gears in each gear.
Thanks everyone for your thoughts. I was figuring around 20%. I thought it might be nice to know where I stand compared to stock. Anyone know the stock rwhp for an 06'?
 

·
Registered
Joined
·
136 Posts
18% is a nice round figure for automatics, slightly less if your manual, Stock 05-06's usually around 330 hp at the rear wheels for automatic, Manual slightly higher, These are SAE numbers on a Dynojet, keep in mind dyno's do read differently. Take it to the track and see what it runs then compare your numbers.
 
1 - 8 of 8 Posts
Top